Bob Newhart, who knows a thing or two about good sitcoms, is sorry to see “Frasier” signing off tonight after 11 seasons.

“I know some of the [‘Frasier’] writers – they’re excellent, and Kelsey [Grammer] and I did a thing for Showtime [‘Doc Waddems’] and it was great fun working with him,” Newhart told me yesterday. “You always want to work with someone strong, and Kelsey gives you that.

“I watch ‘Frasier,’ ‘Friends’ and ‘Sex and the City’ because the writing is so good,” said Newhart. “I don’t watch anything with a laugh track – the minute I hear a laugh track I switch. It’s not the genre I grew up in. ‘I Love Lucy,’ ‘The Honeymooners,’ ‘All in the Family,’ ‘Mary Tyler Moore’ – we all did shows in front of a live audience, and you lived and died depending on that audience.

“Which isn’t to say we didn’t sweeten [the laughter] from time to time, especially the transition from one scene to another because the laughter was cut off,” he said.

“But I think the writing was better and the performances were better because we had that pressure of a live audience.” Speaking of old shows with live audiences, “The Dick Van Dyke Show Revisited,” based on the original “Dick Van Dyke Show” (filmed before a live audience), notched a winning 14.6 million viewers Tuesday (9-10 p.m.). Dick Van Dyke, Mary Tyler Moore and Rose Marie were all back.